Wireless Local Area Networks (WLANs) are used for providing users with access to services and/or network connectivity. WLANs typically follow sets of standards described in the Institute of Electrical and Electronics Engineers (IEEE) 802.11. WLANs may operate in an unlicensed Industrial, Scientific and Medical (ISM) region of the frequency spectrum. For most countries, the communication channels in these bands are located between 2.41 Gigahertz (GHz) and 2.48 GHz (known as 2.4 GHz band or 2.4 GHz) or between 5.17 GHz and 5.82 GHz (known as 5 GHz band or 5 GHz).
The dual band nature of several IEEE 802.11x standards requires antennas to operate at both frequency bands. Additionally, other standards require the use of multiple input multiple output (MIMO) antennas where several transmitting/receiving antennas are operating simultaneously to achieve higher data rates.